DCA Laboratory Testing & Equipment 2

Question 1

Which instrument uses ultraviolet light to reveal fluorescence characteristics in diamonds?

Accepted Answer

UV lamp (longwave/shortwave)

Answer

A UV lamp—available in longwave (365 nm) and shortwave (254 nm) versions—is the standard tool for observing fluorescence in diamonds.

Question 2

A DiamondView instrument is primarily used by gemological laboratories to:

Accepted Answer

Distinguish natural diamonds from CVD and HPHT synthetics

Answer

The DiamondView uses short-wave UV to reveal growth patterns (cuboidal vs. triangular) that differentiate synthetic diamonds from naturals.

Question 3

When using a darkfield loupe, the illumination source is positioned so that light:

Accepted Answer

Enters from the sides so the background appears dark

Answer

Darkfield illumination directs light from the sides, making the background dark and causing internal features to appear bright and visible.

Question 4

Which property does a thermal conductivity probe (diamond tester) measure to separate diamond from simulants?

Accepted Answer

Heat dissipation rate

Answer

Diamond is an exceptional thermal conductor; the probe detects how rapidly heat transfers through the stone, distinguishing diamond from most simulants.

Question 5

A Presidium Duo tester adds electrical conductivity testing to thermal testing primarily to distinguish diamond from:

Accepted Answer

Moissanite

Answer

Moissanite conducts heat similarly to diamond, but it also conducts electricity; the dual thermal/electrical test reliably separates the two.

(DCA) Certified Diamond Council of America Diamond Specialist Practice Test

(DCA) Certified Diamond Council of America Diamond Specialist Practice Test

DCA Laboratory Testing & Equipment 2